Oral food challenge meal formulations

ABSTRACT

This invention relates to kits including novel oral food challenge meal formulations. In particular, the invention also relates to kits including novel oral food challenge meal formulations, wherein the placebo dose formulation is indistinguishable from non-placebo dose formulations.

This invention relates to kits including novel oral food challenge mealformulations. In particular, the invention also relates to kitsincluding novel oral food challenge meal formulations, wherein theplacebo dose formulation is indistinguishable from non-placebo doseformulations. The invention also relates to novel oral food challengemeal formulations, to methods of using the kits and the novel oral foodchallenge meal formulations and to a use of an additive compound toimprove the properties of an oral food challenge meal formulation. Inparticular, the invention relates to novel oral food challenge mealformulations having improved taste and/or texture masking properties forthe allergen contained in the formulation.

BACKGROUND

Oral food challenges are generally considered to be the gold-standardfor diagnosis of food related adverse reactions to foods, includingIgE-mediated reactions, especially when performed in a double-blind,placebo-controlled fashion ¹. The original concept was described in 1949at which time it was suggested that food should be given in such a waythat the patient is unaware of its nature ².

Oral food challenges are usually undertaken to confirm whether anindividual has a clinical allergy and can drive treatment plansincluding elimination diets and food avoidance, as well as prescriptionof rescue medication should a patient inadvertently consume a problemfood ³. There have been several position papers on diagnosis of foodallergy which have focussed primarily on the clinical aspects ofundertaking double blind placebo controlled food challenges (DBPCFC),culminating in the recently published PRACTALL consensus paper ⁴.

Much effort has focussed in the clinical community on harmonisingclinical protocols and stopping criteria but little consideration hasbeen given to standardisation of the agents and food vehicles used forfood challenges, or for dose verification. A key attribute of a foodallergen challenge is to blind or mask the flavour and texture of the“active” allergenic food, to provide a placebo dose (without allergen)and active dose (containing allergenic ingredient) where the patientcannot tell which dose they are being given. This has resulted in aplethora of different approaches and recipes, includes various cookedand baked products, cakes and milks shakes, and different methods toassess the efficacy of blinding, including triangle testing, a sensorytest used by the food industry to compare products ⁵⁻⁷.

It is generally accepted that allergenic foods should be used in theirusual edible form and this was the approach that was adopted in theEuroPrevall project. In the EuroPrevall project, a chocolate dessertbase formulation was developed which was capable of blinding a varietyof commercially available dry powdered food ingredients and is anambient shelf-life stable product by virtue of its low water activity^(8,9). This was done to ease the issues of cost-effective shipping andshelf-life requirements for the multi-centre, transnational project. Thematrix has been used to collect a variety of challenge data includingpeanut, hazelnut, celery spice (celeriac) and fish powder¹⁰. It isreconstituted at the point of use by addition of potable water, storedchilled (2-8° C.) and used within 24 h of rehydration. To date challengemeal formulations have generally fallen short of the requirement ofblinding or masking the flavour and texture of the “active” allergenicfood. For example, the EuroPrevall project describes that, althoughhazelnut allergen was successfully masked, the same could not be saidfor celeriac as 30/37 panellists (i.e. 81%) without nose clips and 27/35panellists (i.e. 77%) were able to correctly identify the differencebetween the placebo sample and the ‘high-allergen’ sample. Thepanellists in this study reported the ‘high-allergen’ dessert as havinga more ‘grainy’, less ‘smooth’ texture and less ‘sweet’, more ‘bitter’taste and, consequently, less ‘chocolate’ flavour.

OBJECTS OF THE INVENTION

It is an aim of the present invention to provide an oral food challengemeal formulation having taste-masking properties for an allergen presentin the formulation.

It is also an aim of the present invention to provide an oral foodchallenge meal formulation having texture-masking properties for anallergen present in the formulation.

It is also an aim of the present invention to provide an oral foodchallenge meal formulation having taste-masking properties such that achallenge meal formulation containing an allergen is indistinguishablefrom a challenge meal formulation in which the allergen is absent (i.e.a placebo challenge meal formulation).

It is also an aim of the present invention to provide an oral foodchallenge meal formulation having texture-masking properties such that achallenge meal formulation containing an allergen is indistinguishablefrom a challenge meal formulation in which the allergen is absent (i.e.a placebo challenge meal formulation).

The present invention achieves one or more, e.g. all, of the abovelisted aims.

SUMMARY OF THE DISCLOSURE

In accordance with the present invention there is provided a kitcomprising:

a challenge meal formulation comprising no food allergen (i.e. a placebochallenge meal formulation); and

a challenge meal formulation comprising allergen, wherein the allergenis present in the challenge meal formulation in an amount of more thanabout 10% w/w and less than about 25% w/w (i.e. a high-dose, non-placebochallenge meal formulation);

wherein the placebo challenge meal formulation comprises an additivepresent in an amount of up to about 1.5% w/w of the oral food challengemeal formulation, wherein the additive is selected from the groupconsisting of: maltodextrin, dextrin, cyclodextrin and combinationsthereof.

The kits of the present invention differ from conventional kits in thatthe placebo formulation includes an additive selected from the groupconsisting of: maltodextrin, dextrin, cyclodextrin and combinationsthereof. Thus, the original formulation developed for the EuroPrevallproject⁸ has been modified to allow inclusion of increased amounts ofallergenic ingredient whilst maintaining blinding (e.g. texture and/ortaste blinding). A key aspect of the new invention is being able tomanipulate the texture of the placebo and active doses to enable them tobe matched.

In accordance with the present invention there is provided a method ofdiagnosing a food allergy comprising:

-   -   a) administering to a subject a challenge meal formulation of        the invention comprising no food allergen (a placebo challenge        meal formulation); or a challenge meal formulation of the        invention comprising allergen present in the challenge meal        formulation in an amount of more than about 10% w/w and less        than about 25% w/w (i.e. a high-dose, non-placebo challenge meal        formulation), wherein the presence or absence of food allergen        in the challenge meal formulation is not known to the subject;    -   b) monitoring for an allergic response;    -   c) grading the allergic response;    -   d) repeating steps a) to c) with a different challenge meal        formulation until all challenge meal formulations have been        administered;    -   e) correlating the graded allergic response with the known level        of food allergen; and    -   f) diagnosing whether or not the subject has a food allergy.

In accordance with the present invention there is provided a use of anadditive in a placebo challenge meal formulation of a kit comprising aplacebo dose formulation and a high-dose, non-placebo dose formulationcomprising an allergen present in the challenge meal formulation in anamount of more than about 10% w/w and less than about 25% w/w, whereinthe additive is selected from the group consisting of maltodextrin,dextrin, cyclodextrin and combinations thereof, the use being to makethe placebo dose formulation indistinguishable from the high-dose,non-placebo dose formulation.

DESCRIPTION OF THE FIGURES

FIG. 1: Oscillatory rheology showing (A) Dynamic strain sweep plots;(B): Dynamic frequency plots; (C) Flow sweep for placebo, low peanut andhigh peanut doses in conventional EuroPrevall chocolate dessert matrixformulations. In panels (A) and (B) the closed symbols represent G′ andopen symbols G″ measurements respectively whilst triangles and squaresrepresent replicate measurements made on two different pots ofreconstituted challenge meal. Low peanut dose, high peanut dose andplacebo formulations are annotated on the plots

FIG. 2: Oscillatory rheology showing (A) Dynamic frequency plots (inwhich G′ and G″ are plotted separately) for the high dose and placeboreformulations; (B) Dynamic frequency tests (in which G′ and G″ areplotted as a ratio) for placebo (squares), low peanut (circles) and highpeanut (triangles) dose reformulations; and (C) Flow sweep for placebo(squares), low peanut (circles) and high peanut (triangles) dosereformulations.

DETAILED DESCRIPTION OF THE DISCLOSURE

Kits Comprising Placebo and Non-Placebo Oral Food Challenge MealFormulations:

In accordance with the present invention there is provided a kitcomprising:

a challenge meal formulation comprising no food allergen (i.e. a placebochallenge meal formulation); and

a challenge meal formulation comprising allergen, wherein the allergenis present in the challenge meal formulation in an amount of more thanabout 10% w/w and less than about 25% w/w (i.e. a high-dose, non-placebochallenge meal formulation);

wherein the placebo challenge meal formulation comprises an additivepresent in an amount of up to about 1.5% w/w of the oral food challengemeal formulation, wherein the additive is selected from the groupconsisting of: maltodextrin, dextrin, cyclodextrin and combinationsthereof.

In an embodiment, the kit of the present invention comprises: (i) achallenge meal formulation comprising no food allergen, wherein thechallenge meal formulation comprises from about 0.05% w/w to about 1.5%w/w additive; and (ii) a challenge meal formulation comprising more than10% w/w and less than about 25% w/w of allergen. Preferably, thepresence or absence of food allergen in the challenge meal formulationis not known to the subject.

In an embodiment, the high-dose allergen formulations includeformulations having more than about 10% w/w to about 25% w/w; more thanabout 10 w/w to about 24% w/w; more than about 10 w/w to about 23% w/w;more than about 10 w/w to about 22% w/w; more than about 10 w/w to about21% w/w; more than about 10 w/w to about 20% w/w; more than about 10%w/w to about 19% w/w; more than about 10% w/w to about 18% w/w; morethan about 10% w/w to about 17% w/w; more than about 10% w/w to about16% w/w; or more than about 10% w/w to about 15% w/w allergen component.

In an embodiment, the high-dose allergen formulations includeformulations having more than about 10% w/w to about 25% w/w; more thanabout 11 w/w to about 25% w/w; more than about 12 w/w to about 25% w/w;more than about 13 w/w to about 25% w/w; more than about 14 w/w to about25% w/w; more than about 15 w/w to about 25% w/w; more than about 16%w/w to about 25% w/w; more than about 17% w/w to about 25% w/w; morethan about 18% w/w to about 25% w/w; more than about 19% w/w to about25% w/w; or more than about 20% w/w to about 25% w/w allergen component.

In line with the teaching of the present invention, in a kit comprisinga placebo dose formulation and a high-dose, allergen containingformulation, the presence of the additive in the placebo doseformulation matches the texture of this formulation with the texture ofthe high-dose allergen containing formulation (such that the placebo andhigh-dose allergen containing formulation are indistinguishable).

In accordance with the present invention there is provided a kit of thepresent invention for use in diagnosing a food allergy.

In an embodiment, the challenge meal formulation of the kit of theinvention further comprises: a matrix formation component; a texturizingcomponent (i.e. a texture compensating component); and a flavour/colourmasking component. The additive component (i.e. the maltodextrin,dextrin and/or cyclodextrin) component of the challenge meal formulationof the kit of the invention may be, but is not necessarily, described asbeing a part of the texture compensatory component.

Formulations comprising an allergen component are non-placeboformulations. Formulations not including an allergen component areplacebo formulations.

Additive Component (i.e. Maltodextrin, Dextrin and/or CyclodextrinComponent):

In an embodiment, the additive component is present in the placebochallenge meal formulation in an amount of no more than about 1.5% w/w;no more than about 1.4% w/w; no more than about 1.3% w/w; no more thanabout 1.2% w/w; no more than about 1.1% w/w; no more than about 1.0%w/w; no more than about 0.9% w/w; no more than about 0.8% w/w; no morethan about 0.7% w/w; no more than about 0.6% w/w; or no more than about0.5% w/w.

In an embodiment, the additive component is present in the placebochallenge meal formulation in an amount of more than 0.05% w/w. In anembodiment, the additive component is present in the placebo challengemeal formulation in an amount of more than 0.1% w/w.

In an embodiment, the additive component is also present in thenon-placebo challenge meal formulation. In an embodiment, the additivecomponent is also present in the non-placebo challenge meal formulationin an amount of no more than about 1.5% w/w; no more than about 1.4%w/w; no more than about 1.3% w/w; no more than about 1.2% w/w; no morethan about 1.1% w/w; no more than about 1.0% w/w; no more than about0.9% w/w; no more than about 0.8% w/w; no more than about 0.7% w/w; nomore than about 0.6% w/w; or no more than about 0.5% w/w. In anembodiment, the additive component is also present in the non-placebochallenge meal formulation in an amount of more than 0.05% w/w. In anembodiment, the additive component is also present in the non-placebochallenge meal formulation in an amount of more than 0.1% w/w.

Preferably, the additive component is present in the placebo challengemeal formulation in an amount of from about 0.05% w/w to about 1.5% w/w.More preferably, the additive component is present in the placebochallenge meal formulation in an amount of from about 0.05% w/w to about1.0% w/w. More preferably, the additive component is present in theplacebo challenge meal formulation in an amount of from about 0.05% w/wto about 0.5% w/w. The additive component may be present in the placebochallenge meal formulation in an amount of from about 0.05% w/w to about0.4% w/w, from about 0.05% w/w to about 0.3% w/w, from about 0.1% w/w toabout 0.5% w/w or from about 0.2% w/w to about 0.5% w/w.

The additive component may also be present in the non-placebo challengemeal formulation in an amount of from about 0.05% w/w to about 1.5% w/w.The additive component may also be present in the non-placebo challengemeal formulation in an amount of from about 0.05% w/w to about 1.0% w/w.The additive component may also be present in the non-placebo challengemeal formulation in an amount of from about 0.05% w/w to about 0.5% w/w.The additive component may also be present in the non-placebo challengemeal formulation in an amount of from about 0.05% w/w to about 0.4% w/w,from about 0.05% w/w to about 0.3% w/w, from about 0.1% w/w to about0.5% w/w or from about 0.2% w/w to about 0.5% w/w.

The amount of additive component in the placebo challenge mealformulation is important as this is determinate of the texture of theformulation (e.g. by the degree of emulsification, stability and/orhomogeneity of the formulation).

In an embodiment, the high-dose allergen formulation includessubstantially no additive. In an embodiment, the high-dose allergenformulation includes 0% w/w additive.

In an embodiment, the additive component comprises maltodextrin. In analternate embodiment, the additive component comprises dextrin. In analternate embodiment, the additive component comprises cyclodextrin.

Preferably the additive component comprises maltodextrin. Preferably,the maltodextrin is present in the formulation, e.g. the non-placeboformulation, in an amount of from about 0.05% w/w to about 0.5% w/w.

Matrix Formation Component:

In an embodiment, the matrix formation component is present in theformulation in an amount of from about 20% w/w to about 60% w/w; fromabout 25% w/w to about 55% w/w; or from about 30% w/w to about 50% w/w.

In an embodiment, the matrix formation component comprises a starchcomponent and sucrose.

In an embodiment, the starch component of the matrix formation componentcomprises a cold swelling starch or a pregelatinised modified starch.Preferably, a cold swelling starch as cold hydrating viscosifying agentis employed as the starch component of the matrix formation component.In a preferred embodiment of the cold swelling starch is selected fromthe group consisting of: Ultratex 2™, Ultratex 2000™, Ultratex 3™,Ultratex 4™, Ultratex SR™, Ultratex HV™, Instant Clearjel™, Ultrasperse3™, Ultrasperse™ IMF, Ultrasperse 5™, Ultrasperse A™, NOVATION Endura0100, NOVATION Prima 300, NOVATION 8300, NOVATION 3300, NOVATION 9230,NOVATION 9330, and combinations thereof. Most preferably the starchcomponent of the matrix formation component is Ultratex 4™. Thementioned examples are available from Ingredion.

In an embodiment, the starch component is present in the formulation inan amount of from about 10% w/w to about 25% w/w. The starch componentmay be present in the formulation in an amount of from about 10% w/w toabout 24% w/w, from about 10% w/w to about 23% w/w, from about 10% w/wto about 22% w/w, from about 10% w/w to about 21% w/w, from about 10%w/w to about 20% w/w or from about 10% w/w to about 19% w/w. The starchcomponent may be present in the formulation in an amount of from about11% w/w to about 25% w/w, from about 12% w/w to about 25% w/w, fromabout 13% w/w to about 25% w/w or from about 14% w/w to about 25% w/w.Preferably, the starch component is present in the formulation in anamount of from about 14% w/w to about 19% w/w.

In an embodiment, the sucrose component is present in the formulation inan amount of from about 15% w/w to about 30% w/w. The sucrose componentmay be present in the formulation in an amount of from about 15% w/w toabout 29% w/w, from about 15% w/w to about 28% w/w, from about 15% w/wto about 27% w/w or from about 15% w/w to about 26% w/w. The sucrosecomponent may be present in the formulation in an amount of from about16% w/w to about 30% w/w, from about 17% w/w to about 30% w/w, fromabout 18% w/w to about 30% w/w or from about 19% w/w to about 30% w/w.Preferably, the sucrose component is present in the formulation in anamount of from about 18% w/w to about 28% w/w. More preferably, thesucrose component is present in the formulation in an amount of fromabout 18% w/w to about 27% w/w.

Preferably the matrix formation component comprises sucrose and Ultratex4™. Preferably, the sucrose is present in the formulation in an amountof from about 18% w/w to about 26% w/w and the Ultratex 4™ is present inthe formulation in an amount of from about 14% w/w to about 19% w/w.

Texturizing Component:

As mentioned above, the additive component (i.e. the maltodextrin,dextrin and/or cyclodextrin) component of the formulation may be, but isnot necessarily, described as being a part of the texturizing component(i.e. texture compensatory component).

In an embodiment, the texturizing component is present in theformulation in an amount of from about 10% w/w to about 35% w/w; fromabout 15% w/w to about 30% w/w; or from about 20% w/w to about 25% w/w.

In an embodiment, the texturizing component comprises an oil componentand a surfactant.

In an embodiment, the oil component of the texturizing componentcomprises a fat or fat blends selected from the group consisting of:highly refined, bleached and deodorised oils. Preferably, the oilcomponent of the texturizing component is selected from the groupconsisting of: maize oil, sunflower oil, rapeseed oil, corn oil, lowmelting fats and combinations thereof. In an embodiment, the oilcomponent of the texturising component is a non-allergenic species andof non-dairy origin. Preferably, the oil component of the texturizingcomponent comprises highly refined oil or maize oil.

In an embodiment, the oil component is present in the formulation in anamount of from about 15% w/w to about 30% w/w. The oil component may bepresent in the formulation in an amount of from about 15% w/w to about29% w/w, from about 15% w/w to about 28% w/w, from about 15% w/w toabout 27% w/w, from about 15% w/w to about 26% w/w or from about 15% w/wto about 25% w/w. The oil component may be present in the formulation inan amount of from about 16% w/w to about 30% w/w, from about 17% w/w toabout 30% w/w, from about 18% w/w to about 30% w/w, from about 19% w/wto about 30% w/w or about 20% w/w to about 30% w/w. Preferably, the oilcomponent is present in the formulation in an amount of from about 20%w/w to about 25% w/w. More preferably, the oil component is present inin the formulation in an amount of from about 21% w/w to about 24% w/w.Still more preferably, the oil component is present in in theformulation in an amount of from about 22% w/w to about 24% w/w. Mostpreferably, the oil component is present in in the formulation in anamount of from about 22% w/w to about 23% w/w.

In an embodiment, the surfactant component of the texturizing componentis selected from the group consisting of: lecithin, polyglycerolpolyricinoleate, monoglycerides, distilled monoglycerides, citric acidesters of monoglycerides, di-acetyl acetic acid esters ofmonoglycerides, lactic acid esters of monoglyceride, diglycerides,polyglycerol esters of fatty acids or sorbitan esters of fatty acids andpolyoxyethylene compositions such as sorbitan monopolyoxyethylene(Tween). Preferably, the surfactant component of the texturizingcomponent is selected from the group consisting of: lecithin and apolyoxyethylene composition, such as sorbitan monopolyoxyethylene(Tween). Most preferably, the surfactant component of the texturizingcomponent is Polysorbate 60 (e.g. Tween 60).

In an embodiment, the surfactant component is present in the formulationin an amount of from about 0.1% w/w to about 2% w/w. The surfactantcomponent may be present in the formulation in an amount of from about0.1% w/w to about 1.8% w/w, from about 0.1% w/w to about 1.6% w/w, fromabout 0.1% w/w to about 1.4% w/w, from about 0.1% w/w to about 1.2% w/wor from about 0.1% w/w to about 1.0% w/w. The surfactant component maybe present in the formulation in an amount of from about 0.2% w/w toabout 2% w/w, from about 0.3% w/w to about 2% w/w, from about 0.4% w/wto about 2% w/w or from about 0.5% w/w to about 2% w/w. Preferably, thesurfactant component is present in the formulation in an amount of fromabout 0.5% w/w to about 1.0% w/w. More preferably, the surfactantcomponent is present in the formulation in an amount of from about 0.5%w/w to about 0.9% w/w. Still more preferably, the surfactant componentis present in the formulation in an amount of from about 0.5% w/w toabout 0.8% w/w. Yet still more preferably, the surfactant component ispresent in the formulation in an amount of from about 0.5% w/w to about0.7% w/w. Most preferably, the surfactant component is present in theformulation in an amount of from about 0.5% w/w to about 0.6% w/w.

Preferably the texturizing component comprises Polysorbate 60 and highlyrefined oil or maize oil. Preferably, the Polysorbate 60 is present inthe formulation in an amount of from about 0.5% w/w to about 0.6% w/wand the highly refined oil or maize oil is present in the formulation inan amount of from about 22% w/w to about 23% w/w.

Flavour/Colour Masking Component:

In an embodiment, the flavour/colour masking component is present in theformulation in an amount of from about 10% w/w to about 45% w/w; fromabout 15% w/w to about 40% w/w; or from about 20% w/w to about 35% w/w.

In an embodiment, the flavour/colour masking component comprises ahighly coloured food powder, a grain component and a liquid (e.g. oil)or powder based flavouring selected from the group consisting of:banana, pineapple, cherry, blackcurrant, raspberry, strawberry,blackberry, blueberry, cranberry, plum, coconut, guava, red apple, pear,mango, apricot, peach, chocolate, cocoa, caramel, toffee, molasses,condensed milk, butterscotch, buttery, bubble gum, fudge, cotton candy,vanilla, coffee, cinnamon, ice cream, honey, custard and combinationsthereof.

In an embodiment, the highly coloured food powder of the flavour/colourmasking component is selected from the group consisting of: cocoa,tomato, beetroot, carrot and carob powders. Preferably, the highlycoloured food powder of the flavour/colour masking component is cocoa ortomato powder. Most preferably, the highly coloured food powder of theflavour/colour masking component is cocoa powder. In an embodiment, thehighly coloured food powder of the flavour/colour masking component is ahighly coloured sweet food powder of the flavour/colour maskingcomponent.

In an embodiment, the highly coloured food powder is present in theformulation in an amount of from about 15% w/w to about 30% w/w. Thehighly coloured food powder may be present in the formulation in anamount of from about 15% w/w to about 29% w/w, from about 15% w/w toabout 28% w/w, from about 15% w/w to about 27% w/w, from about 15% w/wto about 26% w/w or from about 15% w/w to about 25% w/w. The highlycoloured food powder may be present in the formulation in an amount offrom about 16% w/w to about 30% w/w, from about 17% w/w to about 30%w/w, from about 18% w/w to about 30% w/w or from about 19% w/w to about30% w/w. Preferably, the highly coloured food powder is present in theformulation in an amount of from about 19% w/w to about 25% w/w.

In an embodiment, the grain component is present in the formulation inan amount of from about 1% w/w to about 10% w/w. The grain component maybe present in the formulation in an amount of from about 1% w/w to about9% w/w, from about 1% w/w to about 8% w/w or from about 1% w/w to about7% w/w. The grain component may be present in the formulation in anamount of from about 2% w/w to about 10% w/w or from about 3% w/w toabout 10% w/w. Preferably, the grain component is present in theformulation in an amount of from about 3% w/w to about 8% w/w.

In an embodiment, the grain component is selected from the groupconsisting of: oatmeal, an edible member of the Poaceae such as theTriticeae family grain (e.g. wheat, barley or spelt), Pryzea (e.g. rice)or Panicoideae (e.g. maize). Preferably, the grain component is oatmeal.In an embodiment, the oatmeal is toasted oatmeal. In an embodiment, theoatmeal is ground oatmeal. Ground oatmeal is prepared by milling theoatmeal to a particle size of about 0.1 to 1 mm, preferably 0.3 to 0.8mm and most preferably about 0.5 mm. In an embodiment, the oatmeal istoasted and ground oatmeal. Toasted and ground oatmeal (prepared bytoasting fine oatmeal and then milling about 0.5 mm) yields a fine, hardand gritty meal which has a sweet and nutty flavour. This component isparticularly useful in challenge meal formulations including peanutallergen.

In an embodiment, the liquid or powder based flavouring is present inthe formulation in an amount of from about 0.1% w/w to about 3% w/w;from about 0.3% w/w to about 2.5% w/w; or from about 0.5% w/w to about2.0% w/w. The liquid or powder based flavouring may be present in theformulation in an amount of from about 0.1% w/w to about 2.4% w/w; fromabout 0.1% w/w to about 2.3% w/w; from about 0.1% w/w to about 2.2% w/w;from about 0.1% w/w to about 2.1% w/w; from about 0.1% w/w to about 2.0%w/w; from about 0.1% w/w to about 1.9% w/w; or from about 0.1% w/w toabout 1.8% w/w. The liquid or powder based flavouring may be present inthe formulation in an amount of from about 0.2% w/w to about 2.5% w/w;from about 0.3% w/w to about 2.5% w/w; from about 0.4% w/w to about 2.5%w/w; from about 0.5% w/w to about 2.5% w/w; from about 0.6% w/w to about2.5% w/w; from about 0.7% w/w to about 2.5% w/w; or from about 0.8% w/wto about 2.5% w/w. Preferably, the liquid or powder based flavouring ispresent in the formulation in an amount of from about 0.8% w/w to about1.8% w/w.

In an embodiment, the liquid or powder based flavouring comprises achocolate flavoured powder. In an embodiment, the liquid or powder basedflavouring comprises a chocolate flavoured powder in combination withone or more of the liquid or powder based flavourings mentioned above.

Preferably the flavour/colour masking component comprises cocoa powder,oatmeal and a liquid or powder based flavouring. Preferably, the cocoapowder is present in the formulation in an amount of from about 19% w/wto about 25% w/w, the oatmeal is present in the formulation in an amountof from about 3% w/w to about 8% w/w and the liquid or powder basedflavouring is present in the formulation in an amount of from about 0.8%w/w to about 1.8% w/w. Preferably the oatmeal is toasted and groundoatmeal.

Allergen Component:

In formulations comprising an allergen component the allergen componentis present in the formulation in an amount of more than about 10% w/wand less than about 25% w/w. It has surprisingly been found in triangletesting experiments that formulations containing larger quantities ofallergen component can be masked in terms of taste and/or texture. Todate, triangle testing experiments of kits including a placebo componentand a high-dose (e.g. 20% w/w allergen dose) had not yielded resultsindicating successful masking of a high-dose allergen component relativeto the placebo component of the kit.

In an embodiment, the allergen component is selected from the groupconsisting of: legumes (such as peanut, soy, lupin), egg, milk (e.g.cows milk), fish, crustaceans, tree nuts and nut-like seeds (such asalmond, cashew, hazelnut, pistachio, walnut, pecan, Brazil nut),sulphites, wheat, other seeds and grains such as mustard, sesame wheat,vegetables, such as celery (celeriac) or fruits, such as apple and peachallergen. In a preferred embodiment, the allergen component is peanutallergen.

In an embodiment, the kit further comprises (in addition to the placeboand high-dose formulation) a low-dose allergen formulation. In anembodiment, the allergen component in the low-dose allergen formulationis present in the formulation in an amount of from about 0.5% w/w toabout 10% w/w, preferably from about 1% w/w to about 10% w/w.

In an embodiment, the allergen component in the low-dose allergenformulation is present in the formulation in an amount of from about 1%w/w to about 9% w/w; about 1% w/w to about 8% w/w; about 1% w/w to about7% w/w; about 1% w/w to about 6% w/w; about 1% w/w to about 5% w/w;about 1% w/w to about 4% w/w; about 1% w/w to about 3% w/w; or about 1%w/w to about 2% w/w allergen component.

Method of Diagnosing a Food Allergy:

In accordance with the present invention there is provided a method ofdiagnosing a food allergy comprising:

-   -   a) administering to a subject a challenge meal formulation of        the invention comprising (i) no food allergen (a placebo        challenge meal formulation); or (ii) a challenge meal        formulation of the invention comprising allergen present in the        challenge meal formulation in an amount of more than about 10%        w/w and less than about 25% w/w (i.e. a high-dose, non-placebo        challenge meal formulation, wherein the presence or absence of        food allergen in the challenge meal formulation is not known to        the subject;    -   b) monitoring for an allergic response;    -   c) grading the allergic response;    -   d) repeating steps a) to c) with a different challenge meal        formulation until all challenge meal formulations have been        administered;    -   e) correlating the graded allergic response with the known level        of food allergen; and    -   f) diagnosing whether or not the subject has a food allergy.

In an embodiment, step (a) of the method further comprises administeringto the subject a low-dose allergen formulation. In an embodiment, theallergen component in the low-dose allergen formulation is present inthe formulation in an amount of from about 0.5% w/w to about 10% w/w,preferably from about 1% w/w to about 10% w/w. In an embodiment, theallergen component in the low-dose allergen formulation is present inthe formulation in an amount of from about 1% w/w to about 9% w/w; about1% w/w to about 8% w/w; about 1% w/w to about 7% w/w; about 1% w/w toabout 6% w/w; about 1% w/w to about 5% w/w; about 1% w/w to about 4%w/w; about 1% w/w to about 3% w/w; or about 1% w/w to about 2% w/wallergen component.

The presence of the additive is particularly important in formulationscontaining no allergen (i.e. placebo dose formulations) and low-doseallergen formulations (i.e. non-placebo, low dose formulations). Thus,in an embodiment, step (a) of the method of diagnosing a food allergycomprises administering to a subject (i) a challenge meal formulation ofthe invention comprising no food allergen, wherein the challenge mealformulation comprises from about 0.05% w/w to about 1.5% w/w additive;(ii) a challenge meal formulation of the invention comprising a low dose(e.g. about 1% w/w to about 10% w/w) of allergen, wherein the challengemeal formulation comprises from about 0.05% w/w to about 1.5% w/wadditive; or (iii) a challenge meal formulation of the inventioncomprising a high dose (e.g. more than about 10% w/w to about 25% w/w)of allergen, wherein the challenge meal formulation comprises 0% w/wadditive, wherein the presence or absence of food allergen in thechallenge meal formulation is not known to the subject.

Definitions

For the avoidance of doubt, it is hereby stated that the informationdisclosed earlier in this specification under the heading “Background”is relevant to the invention and is to be read as part of the disclosureof the invention.

Throughout this specification, whenever a specific value is quoted for atemperature, pressure or time, the temperature, pressure or time quotedis approximate rather than the precise temperature, amount of pressureor amount of time. Nevertheless, the disclosure includes the precisevalue of any such variables which are approximately that value.

Throughout the description and claims of this specification, the words“comprise” and “contain” and variations of them mean “including but notlimited to”, and they are not intended to (and do not) exclude othermoieties, additives, components, integers or steps. Throughout thedescription and claims of this specification, the singular encompassesthe plural unless the context otherwise requires. In particular, wherethe indefinite article is used, the specification is to be understood ascontemplating plurality as well as singularity, unless the contextrequires otherwise.

Features, integers, characteristics, compounds, chemical moieties orgroups described in conjunction with a particular aspect, embodiment orexample of the invention are to be understood to be applicable to anyother aspect, embodiment or example described herein unless incompatibletherewith. All of the features disclosed in this specification(including any accompanying claims, abstract and drawings), and/or allof the steps of any method or process so disclosed, may be combined inany combination, except combinations where at least some of suchfeatures and/or steps are mutually exclusive. The invention is notrestricted to the details of any foregoing embodiments. The inventionextends to any novel one, or any novel combination, of the featuresdisclosed in this specification (including any accompanying claims,abstract and drawings), or to any novel one, or any novel combination,of the steps of any method or process so disclosed.

The reader's attention is directed to all papers and documents which arefiled concurrently with or previous to this specification in connectionwith this application and which are open to public inspection with thisspecification, and the contents of all such papers and documents areincorporated herein by reference.

REFERENCES

-   1 Bock, S. A. et al. Double-blind, placebo-controlled food challenge    (DBPCFC) as an office procedure: a manual. The Journal of allergy    and clinical immunology 82, 986-997 (1988).-   2 Ingelfinger, F. J., Lowell, F. C. & Franklin, W. Gastrointestinal    allergy. The New England journal of medicine 241, 337; passim,    doi:10.1056/nejm194909012410905 (1949).-   3 Niggemann, B. & Beyer, K. Pitfalls in double-blind,    placebo-controlled oral food challenges. Allergy 62, 729-732,    doi:10.1111/j.1398-9995.2007.01396.x (2007).-   4 Sampson, H. A. et al. Standardizing double-blind,    placebo-controlled oral food challenges: American Academy of    Allergy, Asthma & Immunology-European Academy of Allergy and    Clinical Immunology PRACTALL consensus report. The Journal of    allergy and clinical immunology 130, 1260-1274,    doi:10.1016/j.jaci.2012.10.017 (2012).-   5 Vassilopoulou, E. et al. Evaluation and standardisation of    different matrices used for double-blind placebo-controlled food    challenges to fish. Journal of human nutrition and dietetics: the    official journal of the British Dietetic Association 23, 544-549,    doi:10.1111/j.1365-277X.2010.01046.x (2010).-   6 Vlieg-Boerstra, B. J. et al. Development and validation of    challenge materials for double-blind, placebo-controlled food    challenges in children. The Journal of allergy and clinical    immunology 113, 341-346, doi:10.1016/j.jaci.2003.10.039 (2004).-   7 Ronteltap, A. et al. Sensory testing of recipes masking peanut or    hazelnut for double-blind placebo-controlled food challenges.    Allergy 59, 457-460 (2004).-   8 Cochrane, S. A. et al. Development of a standardized low-dose    double-blind placebo-controlled challenge vehicle for the    EuroPrevall project. Allergy 67, 107-113,    doi:10.1111/j.1398-9995.2011.02715.x (2012).-   9 Mackie, A. et al. High fat food increases gastric residence and    thus thresholds for objective symptoms in allergic patients.    Molecular nutrition & food research 56, 1708-1714,    doi:10.1002/mnfr.201200330 (2012).-   10 Ballmer-Weber, B. K. et al. How much is too much? Threshold dose    distributions for 5 food allergens. The Journal of allergy and    clinical immunology 135, 964-971, doi:10.1016/j.jaci.2014.10.047    (2015).

EXAMPLES

The following examples provide various formulations falling within thescope of the present invention.

There is a fine balance between the amount of starch, maltodextrin,polysorbate, and maize oil which will determine the degree ofemulsification and thus stability and homogeneity of the mixture.

The matrix formation is driven by the ability of Ultratex 4 (Starch,hydrogen phosphate, 2-hydroxypropyl ether, CAS 53124-00-8) to form a gelnetwork on addition of water. The key aspect of the invention is themanipulation of the rheological properties of the gel network by theaddition of maltodextrin in the placebo formulation to allow texturalmatching with the active.

Sensory properties of the following formulations have been evaluated byinformal taste panels (n=4-8) to assess blinding with regards totexture. Attributes scored were identified regarding the organolepticproperties of the dessert. Little difference was perceived with regardsodour and flavour attributes between the placebo and allergen containingformulations, including roasted nut flavours. Importantly, no trace ofpeanut could be discerned in the allergen containing formulations. Withregards the texture, no difference in the thickness of the desserts wasperceived and little variation in its smoothness, grittiness orastringent qualities could be discerned.

Example 1

The formulation comprises the following ingredients:

Placebo Peanut containing formulation formulation (% w/w) (% w/w) PeanutFlour 0.00 20 Maltodextrin 0.50 0 Starch (Ultra-TEX-4) 17.00 14.23Toasted Oatmeal 7.67 3.34 Alkalised Cocoa 24.26 19.15 Sucrose 26.0518.74 Maize oil 22.83 22.00 Polysorbitan 60 0.60 0.60 Fruit flavours1.09 1.94 Total 100.00 100.00

Example 2: Sensory Evaluation of Chocolate Mousse Containing PeanutProtein Using the Triangle Test Method for Similarity

In order to diagnose the severity of a peanut allergy, a chocolatemousse product (with different peanut levels) was produced (in line withthe formulations of Example 1). Two samples of chocolate mousse:“Control” (placebo recipe containing no peanut protein) and “Test” (arecipe containing peanut at 20% w/w) were submitted for sensoryevaluation using the Triangle Test Method TES-S-001 (for similarity)using a panel of 42 sensory assessors (selected from the Campden BRITrained Triangle Test Panel).

The samples were submitted as a concentrated dessert format. Prior tothe test the samples were prepared by reconstitution with cold water(mains supply) by the following protocol:

-   -   Pots were stored at ambient temperature (25° C.), and out of        direct sun light prior to reconstitution.    -   The dessert doses were produced in 300 g masses in 800 ml pots.    -   Each 300 g doses were reconstituted as a single dose.    -   Reconstitution was carried out with all placebo desserts first        followed by all the peanut containing doses.    -   Water from the mains supply at Campden BRI was used to        reconstitute.    -   After initial reconstitution the desserts were stored in a        refrigerator between 2-8° C. overnight.    -   700 mls of water was measured out using a measuring jug.    -   100 mls of the measured water was poured into the pot containing        the dry dessert and mixed with the spatula until fully absorbed.    -   The pots were then left at room temperature for 10 minutes.    -   The dessert was emptied into a Kenwood mixer (model number:        Major KM230) with a paddle blade.    -   The remaining 600 mls of water was poured into the now empty        dessert pot and residual dessert was dissolved by gentle mixing.    -   The desert matrix was them mixed on low speed for 2 minutes.    -   A further 100 mls of water was added and mixed on low speed for        2 minutes.    -   A third 100 mls of water was added and mixed on low speed for 2        minutes.    -   Then 200 mls of water was added and mixed on low speed for 2        minutes.    -   The remaining water was added and mixed on low speed for 2        minutes.    -   The final reconstituted dessert was emptied into a coded glass        mixing bowl, covered with tin foil and refrigerated overnight.    -   The above protocol was repeated for each pot working initially        with placebo and then onto the peanut containing dose.    -   Between batches all equipment was washed with hot water and        detergent and then rinsed with copious amounts of clean water.        All equipment was then dried prior to use.

The aim of the test was to determine whether the panel could perceiveany sensory difference(s) between the two samples to determine whetherthe addition of the peanut protein is detectable.

The samples were placed into the applicable coded containers presentedfollowing the experimental design of the test. Each assessor received aheaped teaspoon of sample per coded container.

The samples were evaluated using the Triangle Test Procedure(TES-S-001). In the triangle test assessors are presented with a set ofthree coded samples, two of which are the same and one of which isdifferent. The sets of samples are presented equally often in each ofthe six possible orders; this experimental design minimises any possibleorder and carryover effects.

Forty-two trained assessors are used for each test, twenty-one receiving“test” as the different sample and twenty-one receiving “control” as thedifferent sample. After tasting the three samples in the designatedorder, each assessor is asked to select the “different” sample and todescribe the difference(s) perceived.

The test was carried out in a purpose-built testing room. Each assessorwas required to undertake the tests in an individual booth. The room waspositively pressurised to minimise the entrance of external odours.Coloured lighting was used to mask any colour difference between thesamples. The panel were instructed to palate cleanse with plain crackersand water (bottled) between the samples to minimise sample carry-over.

For a triangle test for similarity using 42 assessors, a maximum numberof 16 correct responses are required to establish similarity between thetwo samples. The results show that 10 of the 42 assessors correctlyidentified the odd or different sample. It can therefore be concludedthat the samples are statistically similar at the 5% Beta (β) and 30% Pdselected levels, that is, we are 95% confident that only 30% ofdiscriminators can detect a difference.

Alpha (α)—probability of concluding that a perceptible difference existswhen one does not

Beta (β)—probability of concluding that no perceptible difference existswhen one does

Pd—maximum allowable proportion of distinguishers

Reference: Sensory Analysis Methodology—Triangle Test BS EN ISO 4120:2007

The test results above indicate that the two samples are statisticallysimilar at the selected levels (5% Beta (β) and 30% Pd) i.e. nosignificant difference was detected between the two chocolate moussesamples: Test (20% w/w peanut recipe) and Control (placebo recipe).

Example 3: The Use of Maltodextrin in Texture Matching for Oral FoodChallenge Meals Based on Cold Swelling Starch

Conventional Formulations:

The EuroPrevall chocolate dessert matrix of the prior art was developedfor diagnosis of food allergy by oral food challenge and is based on thechemically modified cold swelling starch Ultratex 4 [1, 2]. Thechallenge meals are made as a paste, comprising the cold swellingstarch, oil, surfactant, together with the allergenic ingredient. Otheringredients, such as cocoa powder, sugar and flavours, are added toallow blinding of the colour and flavour of the added allergenicingredient. The dessert is then reconstituted by addition of water priorto use.

In the development of oral food challenge meals it is important to matchthe texture of the placebo (no allergen) and high allergen doses. Whenlevels greater than 13.3% (w/w) of allergenic ingredient in the dry baseare added to the give the high dose, the proportion of cold swellingstarch in the formulation is reduced as shown in the below Table. Thisadversely impacts on the gel formation and results in a difference inthe rheological properties of the placebo and high peanut containingchallenges. This is illustrated below for EuroPrevall formulation No 4:

Challenge Meal Dessert Base Formulation 4 % (w/w) Ingredient in dessertbase Placebo “Low-dose” “High-dose” Ingredient dessert peanut dessertpeanut dessert Peanut Flour 0.00 0.67 13.33 Starch (Ultra-TEX-4) 19.5319.53 13.47 Toasted Oatmeal 6.67 6.00 3.34 Cocoa powder 18.33 18.3318.33 Sucrose 30.74 30.74 26.60 Maize oil 23.33 23.33 23.33 Polysorbitan60 0.60 0.60 0.60 Orange Oil 0.80 0.80 1.00 Total 100 100 100

The rheological properties of the reconstituted high peanut dose showedsignificant deviations from the placebo and low peanut doses (FIG. 1).This resulted in perceptible differences in texture during sensory panelevaluation, which had to be addressed by reformulating the product.

Reformulation of Oral Food Challenges

Inclusion of higher levels of peanut flour to 17.5 and 20% (w/w of drybase) further increased the textural difference of the placebo andpeanut containing challenge meals. During reformulation of thechallenges it was discovered that addition of maltodextrin to theformulation affected the rheological properties of the reconstituteddessert. This was used as a means of manipulating the rheology of theplacebo and low peanut doses to improve the texture matching with thehigh peanut (20% (w/w) of dry base). This gave rise to the recipe below.

Reacta Biotech Formulation [w/w (%)] Low dose High dose peanut peanutPlacebo (0.67%) (20%) Peanut Flour 0.00 0.67 20.00 Maltodextrin 0.500.50 0.00 Starch (Ultra-TEX-4) 17.00 17.00 14.23 Toasted Oatmeal 7.677.67 3.34 Alkalised Cocoa 24.26 23.54 19.15 Sucrose 26.35 26.29 18.89Maize oil 22.83 22.83 22.00 Polysorbitan 60 0.60 0.60 0.60 Fruitflavours 0.79 0.9 1.79 Total 100.00 100.00 100.00

The rheological properties of the above reformulated compositions wereassessed by UNIMAN working in collaboration with the Edinburgh ComplexFluids Partnership.

Data were obtained showing that on hydration the rheological propertiesof the placebo, low peanut dose and high peanut dose (containing 20%(w/w) in the dry base of peanut flour) were practically identical (FIGS.2A, 2B and 2C) and much improved over the EuroPrevall Formulation 4(FIGS. 1A, 1B and 1C).

The dynamic frequency test showed a slight deviation, with the rheologyof the placebo being marginally less frequency dependent than the lowpeanut and high peanut flour meals. However for the flow sweeps nodifference can be seen between the different doses when maltodextrin isincluded in the formulation.

1. A kit comprising: a challenge meal formulation comprising no foodallergen (i.e. a placebo challenge meal formulation); and a challengemeal formulation comprising allergen, wherein the allergen is present inthe challenge meal formulation in an amount of more than about 10% w/wand less than about 25% w/w (i.e. a high-dose, non-placebo challengemeal formulation); wherein the placebo challenge meal formulationcomprises an additive present in an amount of up to about 1.5% w/w ofthe oral food challenge meal formulation, wherein the additive isselected from the group consisting of: maltodextrin, dextrin,cyclodextrin and combinations thereof.
 2. The kit of claim 1,comprising: a challenge meal formulation comprising no food allergen(i.e. a placebo challenge meal formulation), wherein the challenge mealformulation comprises from about 0.05% w/w to about 1.5% w/w additive;and a challenge meal formulation comprising about 15% w/w to about 25%w/w of allergen, wherein the challenge meal formulation comprisessubstantially no additive.
 3. The kit of claim 1, wherein the allergencomponent is selected from the group consisting of: peanut, soy, egg,sesame seeds, milk, fish, crustaceans, almond, cashew, hazelnut,pistachio, walnut, sulphites, wheat, mustard and celery allergen.
 4. Thekit of claim 3, wherein the allergen component is peanut allergen. 5.The kit of claim 1, wherein the additive component is present in theplacebo formulation in an amount of from about 0.05% w/w to about 1.0%w/w.
 6. The kit of claim 1, wherein the additive component ismaltodextrin.
 7. The kit of claim 1, wherein the formulation furthercomprises: a matrix formation component; a texturizing component; and aflavour/colour masking component.
 8. The kit of claim 7, wherein thematrix formation component comprises a starch component and sucrose. 9.The kit of claim 8, wherein the starch component comprises a coldswelling starch or a pregelatinised modified starch.
 10. The kit ofclaim 8, wherein the sucrose is present in the formulation in an amountof from about 18% w/w to about 26% w/w and the starch component ispresent in the formulation in an amount of from about 14% w/w to about19% w/w.
 11. The kit of claim 7, wherein the texturizing componentcomprises an oil component and a surfactant.
 12. The kit of claim 11,wherein the oil component of the texturizing component comprises highlyrefined oil or maize oil.
 13. The kit of claim 11, wherein thesurfactant component of the texturizing component is Polysorbate
 60. 14.The kit of claim 11, wherein the surfactant is present in theformulation in an amount of from about 0.5% w/w to about 0.6% w/w andthe oil component is present in the formulation in an amount of fromabout 22% w/w to about 23% w/w.
 15. The kit of claim 7, wherein theflavour/colour masking component comprises a highly coloured foodpowder, a grain component and a liquid or powder based flavouringselected from the group consisting of: banana, pineapple, cherry,blackcurrant, raspberry, strawberry, blackberry, blueberry, cranberry,plum, coconut, guava, red apple, pear, mango, apricot, peach, chocolate,cocoa, caramel, toffee, molasses, condensed milk, butterscotch, buttery,bubble gum, fudge, cotton candy, vanilla, coffee, cinnamon, ice cream,honey, custard and combinations thereof.
 16. The kit of claim 15,wherein the highly coloured food powder is cocoa or tomato powder. 17.The kit of claim 15, wherein the grain component is oatmeal.
 18. The kitof claim 15, wherein the liquid or powder based flavouring comprises achocolate flavoured powder.
 19. The kit of claim 15, wherein the highlycoloured food powder is present in the formulation in an amount of fromabout 19% w/w to about 25% w/w, the grain component is present in theformulation in an amount of from about 3% w/w to about 8% w/w and theliquid or powder based flavouring is present in the formulation of theinvention in an amount of from about 0.8% w/w to about 1.8% w/w. 20.(canceled)